Question

1. fill in symbol and the number of valence electrons for the following neutral atoms.

neutral atom symbol number of valence electrons
**aluminum
cl

1. the s sublevel contains a maximum of ____ number of orbitals and ____ number of electrons.

a. 3,10
b. 3,6
c. 1,2
d. 2,1

1. *the abbreviated electron configuration for vanadium (v), is:

a. ar4s²
b. ar4s²3d³
c. ar4s²4d⁸
d. ar4d²5s²

1. **the full electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d⁹ represents the element ______

a. copper
b. phosphorous
c. silver
d. krypton

1. **write the full electron configuration for sulfur.

Explanation:

Step1: Recall aluminum symbol

Aluminum's chemical symbol is Al.

Step2: Determine aluminum's valence electrons

Aluminum has atomic number 13. Its electron - configuration is 1s²2s²2p⁶3s²3p¹, so it has 3 valence electrons.

Step3: Recall chlorine valence electrons

Chlorine (Cl) has atomic number 17. Its electron - configuration is 1s²2s²2p⁶3s²3p⁵, so it has 7 valence electrons.

Step4: Recall s - sublevel properties

The s sublevel has 1 orbital and can hold a maximum of 2 electrons. So the answer for question 2 is c.

Step5: Determine vanadium's abbreviated electron - configuration

Vanadium (V) has atomic number 23. The noble - gas core of argon (Ar) has 18 electrons. The remaining 5 electrons are in 4s² and 3d³. So its abbreviated electron - configuration is [Ar]4s²3d³, answer b for question 3.

Step6: Identify element from electron - configuration

For the electron - configuration 1s²2s²2p⁶3s²3p⁶4s²3d⁹, the total number of electrons is 29. Copper (Cu) has atomic number 29. So the answer for question 4 is a.

Step7: Write sulfur's full electron - configuration

Sulfur (S) has atomic number 16. Its full electron - configuration is 1s²2s²2p⁶3s²3p⁴.

Answer:

1. Aluminum: Symbol - Al, Number of valence electrons - 3; Cl: Number of valence electrons - 7
2. c. 1, 2
3. b. [Ar]4s²3d³
4. a. Copper
5. 1s²2s²2p⁶3s²3p⁴